Abstract:

Objective: This study intends to provide a basis for promoting the application of bamboo scrimber in engineering by studying the variation of tensile strength of bamboo scrimber along the grain under different densities and moisture contents. Method: By referring to《Standard Test Methods for Small Clear Specimens of Timber》(ASTM D143—14), bamboo scrimber specimens with different densities (1.1, 1.2, 1.3 g·cm^?3) and moisture contents (4%, 8%, 12%, 16%, 20%) were selected for orthogonal tensile test, analyzed the tensile failure modes of bamboo scrimber parallel to grain under different density and moisture content, the linear model and parabolic model were used to fit the variation tensile strength of bamboo scrimber parallel to grain with density, and the linear model and ASTM model were used to fit the variation of tensile strength of bamboo scrimber parallel to grain with moisture content. Finality, the coupling model of tensile strength of bamboo scrimber parallel to grain with the influenced of density and moisture content was proposed. Result: The main failure forms of bamboo scrimber parallel to grain under tension were flat failure and oblique failure. The flat failure was more prone to happen with the increasing density of scrimber bamboo. and the oblique failure was more prone to happen with the increasing moisture content of bamboo scrimber. Through experimental research and data fitting, the single parameter model and the two parameter coupling model of the tensile strength of bamboo scrimber parallel to grain were proposed respectively. The theoretical results were in good agreement with the experimental results. Conclusion: Within the density range of this study, the tensile strength of bamboo scrimber parallel to grain increased with the increase of density. The tensile strength of bamboo scrimber parallel to grain decreased with the increase of moisture content. The linear combination model and the ASTM combination model can predict the theoretical value of the tensile strength of bamboo scrimber parallel to grain under the influence of the two parameters. The linear combination model was more convenient to calculate, and it was recommended to use in practical applications.

Key words: bamboo scrimber, parallel to grain, tensile strength, density, moisture content